The present disclosure generally relates to foam mattress assemblies; specifically side rail assemblies of the mattress that exhibit increased airflow.
Foam mattresses such as those formed of polyurethane foam, latex foam, and the like, are generally known in the art. One of the ongoing problems associated with foam mattress assemblies is user comfort. To address user comfort, these mattresses are often fabricated with multiple foam layers having varying properties such as density and hardness, among others, to suit the needs of the intended user. More recently, manufacturers have employed so called memory foam, also commonly referred to as viscoelastic foams, which are generally a combination of polyurethane and one or more additives that increase foam density and viscosity, thereby increasing its viscoelasticity. These foams are often open cell foam structures having both closed and open cells but in some instances may be reticulated foam structures. The term “reticulated” generally refers to a cellular foam structure in which the substantially all of the membrane windows are removed leaving a skeletal structure. In contrast, open cell structures include both open cell (interconnected cells) and closed cells.
When used in a mattress, the memory foam conforms to the shape of a user when the user exerts pressure onto the foam, thereby minimizing pressure points from the user's body. The memory foam then returns to its original shape when the user and associated pressure are removed. However, the return to the original shape is a relatively slow process because of the viscoelastic cellular structure of these types of foams.
Unfortunately, the high density of foams used in current mattress assemblies, particularly those employing memory foam layers, generally prevents proper ventilation. As a result, the foam material can exhibit an uncomfortable level of heat to the user after a period of time. Additionally, these foams can retain a high level of moisture, further causing discomfort to the user and potentially leading to foul odors.
Reticulated memory foams, i.e., foams in which the cellular walls are substantially removed, are known to provide greater airflow. However, because substantially all of the cellular walls have been removed leaving behind a skeletal structure, these foams are inherently weak, provide less load-bearing capabilities relative to other non-reticulated viscoelastic foams, and are subject to fatigue at a rate faster than partially or completely closed cell foam structures. Moreover, reticulated viscoelastic foams require special processing to remove the cellular walls to form the skeletal structure making these foams relatively expensive.
Moreover, much like the foam mattresses described above, the current side rail assemblies, used in the mattress assemblies for edge support, also tend to act as an air dam blocking the flow of air out of the mattress. This can further reduce the ventilation of the mattress assembly and increase the amount of heat and/or moisture retained in the mattress. These side rail assemblies can redirect the flow of air (and heat and moisture) back through the top sleeping surface, thereby adding to the discomfort experienced by the user.
Accordingly, it would be desirable to provide a mattress assembly, especially a side rail assembly including one or more layers of viscoelastic memory foam, with an improved airflow to aid in the dissipation of user heat.